But Democratic candidates, strategists involved in key races say, see Hillary Clinton's potential role as much more limited than it's been in previous years. And they want even less from Bill Clinton -- at least publicly.

The national focus on sexual harassment and workplace power structures has put the Clintons, staples of Democratic politics for three decades, in a complicated position.

Both remain increasingly popular with Democratic voters and can turn out crowds of supporters during arduous midterm campaigns where excitement and media attention come at a premium. The Clintons will certainly hit the trail this year, sources close to both Democrats told CNN, and have already begun fielding preliminary calls from candidates that are ready to get them involved.

But the couple's history with sexual harassment allegations -- most notably during the former president's affair with then-White House intern Monica Lewisnky, and more recently over Hillary Clinton's decision not to fire a staffer accused of sexual harassment during her 2008 campaign -- may make it harder for campaigns in swing districts and states to fully embrace them, strategists involved in key races said.

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For her part, Hillary Clinton is eager to get involved.

She met with Democratic National Committee Chairman Tom Perez at least twice over the last year to discuss rebuilding the committee and how to best improve infrastructure that was seen as lacking during the 2016 campaign, said a party official who did not want to be identified because they were not authorized to talk about details of Democrats' 2018 plans.

Asked about whether the current climate makes it difficult for the Clintons to hit the campaign trail, the official left the decision up to individual candidates and their campaigns.

"Every candidate is going to have to make a determination about who they want on the road with them," the official said. "Every campaign is going to have different needs in each state."

Bill and Hillary Clinton declined to comment for this story.

Hillary's plans

The former secretary of state does plan to be fully involved in the 2018 election, her advisers say.

Clinton has begun fielding requests from 2018 campaigns, one adviser said, and views Onward Together, the super PAC she established after the 2016 election, as a vehicle for her midterm work. Clinton, by virtue of her two failed presidential campaigns, has a massive email list that she could use to raise money for Democratic candidates and committees

Clinton advisers have long pointed to the 2018 election as a way for the former Democratic nominee to fight back against Donald Trump, the man who defeated her. In 2017, when pressed on questions about Clinton resuscitating her own political career, advisers said she was far more interested in the midterms than anything personal.

But so far, candidates don't appear to see either of the Clintons as must-have surrogates.

"Hillary we could probably use in targeted ways, and I think you've seen her out there and she has a dedicated base of support," said one Democratic strategist involved in a competitive 2018 Senate race who did not want to be identified for fear of upsetting the Clintons.

"The Bill question gets very tricky," the strategist said, in a reference to the former president's sexual misconduct. "We have to mean what we say: Zero tolerance means zero tolerance."

"I certainly think the Obamas would be more effective surrogates out on the campaign trail," the strategist said.

That Hillary Clinton lost 10 states where Democratic Senate incumbents are on the ballot in 2018 is another factor that minimizes her appeal as a surrogate or fundraiser, said another Democratic strategist involved in a different competitive 2018 Senate race.

This strategist said campaigns this year will attempt to build on the momentum of the Women's March and the #MeToo movement and the Clintons would not likely be helpful in achieving that goal.

A third Democrat involved in 2018 races said there's less need for the Clintons in this election cycle in part because an energized base has sent candidates' low-dollar, online fundraising soaring.

Other liberal surrogates

Another factor: The party's 2020 presidential prospects are eager to hit the campaign trail.

Figures like New Jersey Sen. Cory Booker and California Sen. Kamala Harris have already begun traveling to fundraisers and events on behalf of 2018 candidates and could draw even more interest than the Clintons as the next Democratic nominating contest comes into focus.

Several Democrats pointed to former Vice President Joe Biden as a commanding presence in areas where Bill Clinton used to be the party's top draw. He campaigned for Doug Jones ahead of Jones' win in Alabama's Senate special election in December, and plans to visit Montana, where Sen. Jon Tester is up for re-election, for a state party event in March.

A Clinton comeback?

Stepping onto the campaign trail would mean Hillary Clinton entering a political world that is vastly different from the one she left in November 2016. While questions around the way she handled accusations against her husband arose during the 2016 campaign -- particularly whether she sought to smear the women accusing Bill Clinton -- they were far from dominant.

That a woman who broke barriers to become the first female candidate on a major party presidential ticket should be a complication in any aspect of a women's movement is an incredible turnaround.

While Clinton has encouraged some women's movements in response to her 2016 loss, she has played no public role in the #MeToo movement other than announcing that she would donate the money disgraced movie mogul Harvey Weinstein contributed to her political campaigns after multiple sexual assault allegations were leveled against him.

The blowback to Clinton's handling of the 2008 accusations against former aide Burns Strider after a woman he worked with accused him of harassment that included inappropriate touching, kissing her forehead and sending her suggestive emails and her initially milquetoast response have been strong, even from longtime Clinton supporters. Patti Solis Doyle, Clinton's campaign manager at the time who recommended Strider, the aide in question, be fired, told CNN Monday that the response was disappointing.

"I very much understand the question I'm being asked as to why I let an employee on my 2008 campaign keep his job despite his inappropriate workplace behavior," Clinton wrote. "The short answer is this: If I had it to do again, I wouldn't."

Bill Clinton complications

The 2018 campaign trail could be even more fraught for Bill Clinton, whose handling of his affair with Lewinsky two decades ago would get even more attention than the limited coverage it received during the 2016 campaign.

A person familiar with Bill Clinton's plans said the former president, who is currently focused on writing a book, has already begun receiving preliminary requests for support and advice from 2018 candidates. Some of the outreach includes 2018 operatives interested in his view of the electorate and messaging that may work, the source said.

Bill Clinton, even 22 years removed from his last campaign, has long been viewed as a tireless campaigning who enjoys few things more than giving a stump speech and working the room afterward. People close to him say that won't be different in 2018.

But a Democratic operative with deep ties to the Clintons admitted that 2018 could be a year in which their power in Democratic politics wanes.

"I will be the first to admit that it makes it a little harder to embrace someone who has either been fairly or unfairly seen as someone who has not taken women's claims are seriously as they should have and that would be Hillary Clinton," said the operative.

But, the operative added, it will likely impact Bill Clinton even more.

"It is going to be far more difficult for him. He is going to be in less demand," the operative said, adding that any event where a candidate who has seized on the #MeToo movement held with the former president "would be seen to be as hypocritical."